Utilities: Get switched on about the PSTN switch off

The analogue network technology that currently enables the UK’s PSTN (public switched telephone network) has become difficult and expensive to maintain. As an infrastructure that is decades-old, the UK Government recognised in the Future Telecoms Infrastructure Review that the PSTN was coming to the end of its life. Industry agreed and announced that it would be switched off by 2025.

What will happen?

In place of the PSTN, the UK’s telephone system will transition to an All-IP set-up, in which all services, including voice calls, shift to the internet protocol (IP). Communications Providers (CPs) such as BT/Openreach and Virgin Media are implementing the change, with trials underway (Salisbury and Mildenhall by Openreach, and Wokingham for Virgin Media’s IP Voice Test Lab). The switch-off will be an opportunity for CPs to modernise their networks and offer a more reliable service, with more innovative products.

However, the PSTN already provides many services, alongside the more well-known “landline” voice calls, including a range of data services to devices such as burglar and social care alarms, point-of-sale card machinery, and telemetry services that connect critical national infrastructure (CNI). Therefore, before the switch-off completes in 2025, a wide variety of companies will need to prepare now.

Impact for energy, water and utilities sectors

While the withdrawal of wholesale line rental (WLR) presents a challenge to many sectors classed as critical, this insight will specifically address the impact on the energy and water industries.

Energy providers and water companies in the UK rely on SCADA (supervisory control and data acquisition) and other industrial control systems to monitor their infrastructure. By design, these systems enable remote data collection and processing, detecting system events and supervisory controls. While many have adapted to the modern developments in networking, open systems architecture, and use of SQL (structured query language), “landlines” still play a crucial role in connecting remote sites.

For example, the utilities sector relies on the PSTN to send and receive voiceband data from sites (like alarms), and some control function such as building access. Alternatives may not be as low-cost or reliable as the voiceband over analogue, or even possible across such long lines. There is also a capital cost to consider for building the digital infrastructure, and cyber security concerns. For remote landline voice services, the impact would also be considerable. Connectivity is also problematic in remote locations, with a lack of satellite or cellular coverage. And let us not forget the security, health and safety, and wellbeing concerns for lone-workers who rely on the PSTN as a “last-resort” communications solution.

What can be done now

Despite the challenges and risks for the energy and utilities sector when the PSTN is switched off, and operational issues in deploying IP services, operators and suppliers can act now to develop a fully resourced plan, based on solution delivery.

In the first instance, contacting your CP is crucial. They will have the information – along with key milestones – to help you implement changes. Tracing the exact locations of PSTN connected sites, functions and criticality will help paint the most accurate picture of data capture.

The PSTN switch-off also presents an opportunity for operators to introduce new technologies (like 5G and LoRaWAN – long range and low-power wide-area networks) for efficiency, reliability, and ultimately, lower cost. A cyber security plan should also be prioritised, including device-to-device threat analysis and use of encrypted data. The preparation and planning that can be completed in the short-term will increase the chances of long-term success in adapting to this new era of telecommunications, as well as reduce the likelihood that critical services will be lost in December 2025.

  • Sophie James

    Sophie James

    Broadband Stakeholder Group, Central Government, Communications Infrastructure, Financial Services
    T 020 7331 2038
  • Teodora Kaneva

    Teodora Kaneva

    Programme Manager | SmarterUK
    T 020 7331 2016

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